Friday, September 28, 2012

New to Missouri, rev.

I really don't know what to say about the site I visited today, a pine woodland burned in late April with thinning slash on the ground:
Late April fires in normal weather/seasonal conditions traditionally hit the midstory pretty hard, but this past April, being advanced two weeks in the greening process, this fire really put the hurt on the canopy. I don't know what to say about a stand replacing fire that was implemented with slash on the ground and years of fuel loading. A few live pine trees remain on the site, and the understory is dominated by incredibly robust fireweed, a few desmodiums (averaging 5 ft. tall in flower--I had stick tights in my hair this afternoon), and a species not documented from Missouri before this fire event.

Missouri's finest botanist, the stellar Justin Thomas of the Institute of Botanical Training, worked plot settings in this burn unit recently, and leave it to Justin to find yet another new-to-Missouri species. It seems that during each growing season I hear of another new-to-Missouri species (almost monthly) that Justin has discovered. He covers more ground than anyone I know in the field, and he has an encyclopedic knowledge of vascular plants. These new species aren't the recently-split varieties, new because they weren't classified as such during the last publication of a Flora. No, Justin finds Gulf Coastal Plain plants in the bootheel, Arkansas plants in White River country, and recently, in this fireweed-dominated burn unit with all the dead pine trees and residual slash, he discovered the pine woodland plant, Eupatorium album, in Missouri. Since the first publication of this post, I have learned that he also found E. album in the gravel washes nearby this site, so this is not a fire-dependent species. 

The plant was almost in seed by the time we saw it last week, having been discovered in flower almost one month ago. In my company (the hand) was a botanist from longleaf pine savanna country, Ft. Benning Georgia, who says that this plant is in pine systems in Georgia, but normally associated with low intensity, frequent ground fires and not blazing hot, stand-replacing fires, the likes of which occurred here in the Ozarks in April. Further, said botanist has never seen a more robust specimen than the ones we saw today which were scattered all over this site. 

In Arkansas, this plant is relatively conservative and occurs in Northwest Arkansas in burn units, with the nearest location to today's site over 100 miles away. E. album is not necessarily tied to exceedingly hot fires, and can be found in typical pine-bluestem systems, the same ecotype desired in the tract visited today. 

We visited other super hot spring fire sites today and didn't find the plant, but found -expectedly- fireweed, pokeweed, and robust panic grasses. Why did E. album appear in Missouri after this extremely hot fire, in the absence of other plants, and in nearby gravel washes? Is this another disturbance dependent species in Missouri?  

Across the road from the new plant site, I found a robust Liatris aspera that reached almost 5 ft. tall, surrounded by others (pictured) which had been summarily clipped off by deer. Burn an Ozark woodland and the overabundant deer will come to eat up nature's food plot, namely the conservative forbs. Like the other Eupatoriums, E. album is likely unpalatable to deer since it was the only forb in the area untouched by the voracious hooved creatures. 



A.L. Gibson said...

Interesting as always, Allison! It's always exciting to discover or see a species new to the state's flora; regardless of what it is. Justin is an incredible botanist and it seems quite appropriate as you mentioned he would make the find.

Eupatorium album is rare in Ohio where I've only seen it growing under mixed oak species on the higher, drier slopes of Shawnee state forest in Scioto Co. (extreme south-central along the Ohio River). I love the inflorescences and their unique look.

Justin R. Thomas said...

Thanks, Allison. I might add to the topic that there are gravel wash communities with rather intact and very intriguing floristic elements on either side of the ridge where you saw the Eupatorium album. Said gravel washes have not burned (the washing removes the leaf litter and thus fire doesn't carry) and have many E. album plants in them. They could have been there for decades (heck, centuries) and not been noticed. These plants are the likely source of the colonization event into the burned area rather than latent seed or long distance dispersal dynamics.

Of course, this is equally speculative and the whole thing is quite mysterious. Either way, they now have many acres of open niches to colonize.